Add ACMCC app source, Supabase backend, and project config

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

supabase/migrations/20260411010158_19f0cdcc-e161-43d8-9a91-8854f77110a3.sql

@@ -0,0 +1,12 @@
+-- Drop the overly permissive homeowner SELECT policy
+DROP POLICY IF EXISTS "Homeowners can read active stripe mappings" ON public.stripe_account_mappings;
+
+-- Create a restricted SELECT policy: homeowners can only read mappings for their own association
+CREATE POLICY "Homeowners can read own association stripe mappings"
+  ON public.stripe_account_mappings
+  FOR SELECT
+  TO authenticated
+  USING (
+    is_active = true
+    AND association_id IN (SELECT get_user_association_ids())
+  );